Laser cleaning method and device for improving uniformity of laser cleaning surface
AssigneeInstitute of Semiconductors, Chinese Academy of Sciences
InventorsXuechun Lin, Zhiyan Zhang, Haijun Yu, Houwang Zhu, Quansheng Zeng, Zhiyong Dong, Hao Liang, Wenhao Ma, Hongyang Wang
Life of this patent
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Abstract
A laser cleaning method and device for improving uniformity of a laser cleaning surface are provided. The laser cleaning method includes: applying a peaked-top sine wave signal to a motor; controlling a galvanometer to swing in a reciprocated manner by the motor; shaping a laser beam emitted by a laser to a linear beam by the reciprocated swing of the galvanometer; and performing laser cleaning using the shaped linear beam.
Claims4
A laser cleaning device for improving uniformity of a laser cleaning surface, wherein the laser cleaning device comprises:
- a laser configured to emit a laser beam;
- a galvanometer configured to shape the laser beam linearly by swing;
- and
- a motor configured to receive a periodical signal and control reciprocated swing of the galvanometer based on the periodical signal,
- wherein the periodical signal is a peaked-top sine wave signal, and the laser beam shaped by the galvanometer is used for laser cleaning;
- wherein the laser cleaning device further comprises a signal generation module configured to generate the peaked-top sine wave signal and transmit the peaked-top sine wave signal to the motor;
- wherein the signal generation module comprises:
- a first signal generator configured to generate a sine wave signal;
- a second signal generator configured to generate a triangular wave signal;
- and a signal converting circuit configured to combine and convert the sine wave signal and the triangular wave signal to obtain the peaked-top sine wave signal;
- wherein the signal converting circuit comprises:
- a first amplitude limiting circuit configured to receive the sine wave signal to generate a flat-top sine signal;
- a second amplitude limiting circuit configured to receive the triangular wave signal to generate a flat-top triangular wave signal;
- a subtraction circuit configured to subtract the flat-top triangular wave signal from the triangular wave signal to obtain a special triangular wave signal, such that the special triangular wave signal has a same period as the triangular wave signal and in the period of the special triangular wave, the special triangular wave comprises a first part, a second part, a third part, a fourth part and a fifth part which are connected in sequence, wherein each of the first part, the third part, and the fifth part is at zero voltage, the second part is a positive triangular pulse, and the fourth part is a negative triangular pulse spaced apart from the first part by the third part;
- and
- an addition circuit configured to add the flat-top sine signal with the special triangular wave signal to obtain the peaked-top sine wave signal, such that in a period of the peaked-top sine wave signal, the peaked-top sine wave signal has first top portion in form of a positive triangular wave and a second top portion in form of a negative triangular wave.
Dependencies are inferred from the claim text.